This invention relates to a multi-core hydraulic duct and in particular to such a duct which carries high pressure hydraulic fluid for hydraulic systems in underground mine workings.
A multi-core duct usually consists of a plurality of hydraulic conduits bunched together within a flexible protective sleeve. Such high pressure multi-core ducts are used in mine workings primarily for the supply of pressure medium to, and the hydraulic control of, a hydraulically advanceable mine roof support assembly in for example, a longwall working. The conduits themselves are flexible, and the protective sleeve is usually constituted by a spring steel strip which is wound helically around the bunch of conduits. Such a multicore high-pressure duct is relatively heavy and is too stiff to bend as required.
It is the aim of the invention to produce a multicore duct, especially for hydraulic mine roof support assemblies in underground mine workings, which does not suffer from these disadvantages.